Laminated passivation structure of solar cell and preparation method thereof

Patent metadata

Field	Value
Publication number	US-12563856-B2
Application number	US-202117434085-A
Country	US
Kind code	B2
Filing date	May 21, 2021
Priority date	Jan 19, 2021
Publication date	Feb 24, 2026
Grant date	Feb 24, 2026

Abstract

A laminated passivation structure of solar cell and a preparation method thereof are disclosed herein. The laminated passivation structure of solar cell includes a P-type silicon substrate, a first dielectric layer, a second dielectric layer, and a third dielectric layer sequentially arranged on the back side of the P-type silicon substrate from inside to outside. The preparation method includes generating a first dielectric layer on the back surface of the P-type silicon substrate, and then sequentially depositing a second dielectric layer and a third dielectric layer on the first dielectric layer.

First claim

What is claimed is:

1 . A laminated passivation structure of a solar cell comprising:
a P-type silicon substrate; a first dielectric layer, a second dielectric layer, and a third dielectric layer sequentially arranged on a back surface of the P-type silicon substrate from inside to outside; and an additional dielectric layer disposed on a front surface of the P-type silicon substrate, wherein the first dielectric layer is a silicon oxide layer with a thickness of 1 to 10 nm, the second dielectric layer is a silicon oxynitride layer with a thickness of 1 to 50 nm, the third dielectric layer is a silicon nitride layer with a thickness of 1 to 150 nm and the additional dielectric layer is a silicon carbide layer, wherein the second dielectric layer comprises, sequentially arranged from the P-type silicon substrate:
a first silicon oxynitride film with a refractive index ranging from 1.5 to 2.2;
a second silicon oxynitride film with a refractive index ranging from 1.6 to 2.3; and
a third silicon oxynitride film with a refractive index ranging from 1.7 to 2.4,
wherein the refractive index of the first silicon oxynitride film is less than the refractive index of the second silicon oxynitride film, and the refractive index of the second silicon oxynitride film is less than the refractive index of the third silicon oxynitride film, and wherein the third dielectric layer is a laminated film structure comprises, sequentially arranged from the P-type silicon substrate:
a first silicon nitride film with a refractive index ranging from 1.5 to 2.2;
a second silicon nitride film with a refractive index ranging from 1.6 to 2.3; and
a third silicon nitride film with a refractive index ranging from 1.7 to 2.4, and
wherein the refractive index of the first silicon nitride film is less than the refractive index of the second silicon nitride film, and the refractive index of the second silicon nitride film is less than the refractive index of the third silicon nitride film.

2 . The laminated passivation structure of a solar cell according to claim 1 , further comprising a N++ heavily diffused region, a N+ lightly diffused region, a fourth dielectric layer and a fifth dielectric layer sequentially arranged on the front surface of the P-type silicon substrate from inside to outside, and
wherein the additional dielectric layer is the fifth dielectric layer.

3 . The laminated passivation structure of a solar cell according to claim 2 , wherein the fourth dielectric layer is a SiO 2 layer.

4 . The laminated passivation structure of a solar cell according to claim 2 , wherein a thickness of the fourth dielectric layer is 1 to 10 nm.

5 . The laminated passivation structure of a solar cell according to claim 2 , further comprising a front Ag electrode contacting with the N++ heavily diffused region through the fifth dielectric layer and the fourth dielectric layer.

6 . The laminated passivation structure of a solar cell according to claim 1 , further comprising an aluminum back field connecting with the P-type silicon substrate after passing through the third dielectric layer, the second dielectric layer, and the first dielectric layer.

7 . The laminated passivation structure of a solar cell according to claim 2 , wherein a diffusion sheet resistance of the N+ lightly diffused region is 120 to 300 ohm/sq.

8 . The laminated passivation structure of a solar cell according to claim 2 , wherein a diffusion sheet resistance of the N++ heavily diffused region is 40 to 100 ohm/sq.

9 . The laminated passivation structure of a solar cell according to claim 1 , wherein the front surface of the P-type silicon substrate is sequentially provided with an emitter junction region and a first SiNx film from inside to outside, an Ag electrode passes through the first SiNx film and then connects with the emitter junction region, and
wherein the first dielectric layer is a second SiO 2 film, the second dielectric layer is a SiOxNy film, and the third dielectric layer is a second SiNx film, an aluminum back field passes through the second SiNx film, the SiOxNy film and the second SiO 2 film in sequence and then contacts with the P-type silicon substrate.

10 . The laminated passivation structure of a solar cell according to claim 9 , wherein the emitter junction region comprises a N++ heavily diffused region, a N+ lightly diffused region and a first SiO 2 film which are arranged on the front surface of the P-type silicon substrate from inside to outside.

11 . The laminated passivation structure of a solar cell according to claim 10 , wherein a diffusion sheet resistance of the N+ lightly diffused region is 120 to 180 ohm/sq, and a diffusion sheet resistance of the N++ heavily diffused region is 40 to 100 ohm/sq.

Assignees

• Hanwha Solution Corp
• Hanwha Solutions Corp

Inventors

• Zhang Xueling
• Liu Wei
• Chen Hong
• Jian Lei
• Chen Yifeng

Classifications

• H10F77/315

  the coatings being antireflective or having enhancing optical properties · CPC title

• H10F77/211

  for photovoltaic cells · CPC title

• H10F71/1221

  comprising polycrystalline silicon · CPC title

• H10F10/14

  Photovoltaic cells having only PN homojunction potential barriers · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title